Thermostatically controlled signal



Nov. 13, 1934. U FQR D 1,980,194

' THERMOSTATICALLY C ONTROLLED SIGNAL Filed April 27. 1931 2 Sheets-Sheet l INVENTOR JOHN J. F 0R0 Nov. 13, 1934.

J. J. FORD 1,980,194

THERMOSTATICALLY CONTROLLED S IGNAL Filed April 27, 1931 2 Sheets-Sh eet 2 I H III HWI TORN EY Patented Nov. 13, 1934 ackson; Heights, N. Y., assign or to flew'iork, N. Y.,- a cor- Iork g 1 Application April 271, 1931,.Serial No; 533.071

2 Claims. 101. 171411) This invention to, improvements in signalling devices and has particular reference to a thermostaticallycontrolled fire-alarm. M

, An object of the invention is to providean im- 5 proved of vsimple, practical and compact construction wherein a thermostatic switch is utilized to control the energization of an electromagnetic device for the purpose of operating an audible signal. p I 1.0 The above and other objectswill appear more clearly from the following detailed description when taken in connection with the accompanying drawings which illustrate preferred embodiments of the inventive idea.

In the drawings:-

Fig. 1 is a vertical longitudinal section through a signalling device embodying one form of the invention;

Fig. 2 is a front elevation partly broken awa a) and shown in section, and with the audible signal respectively illustrating a slightly different form of the invention; and

Fig. 6 is a diagrammatic view of a circuit employed in the embodiment of Figs. 4 and 5.

Referring more particularly to Figs. 1 to 3, the

- device is shown as comprising a casing 7 of rectangular formation, open at its front and adapted to be attached to a suitable support by means of a bracket 8. -In the upper and lower ends of the casing 7 there are suitably secured plates 9 and 10 of insulated material, said plates projecting beyond the open end of the casing and being connected by a supporting member or strip 11. At approximately the center of said member 11 the same has mounted thereon an audible signal 12 4c in the form of a gong which is substantially centered with respect to the casing 7 so that the latter will project into the open side of the gong,

as shown in Fig. l.

Mounted within the casing 7 and depending from the plate 9 in a vertical position is an electromagnetic device 13 in the form of a solenoid one terminal of the winding of which is permanently connected to a source of current supply through the conductor 14. The core of said solenoid is w extended beyond the lower end of the winding in the form of a sleeve 15 the lower end of which rests upon the insulated plate 10 and adjacent said lower end the sleeve is provided with opposed openings 16 therein, the purpose of which will presently appear. The plunger 17 of the solenoid is movable axially through the core and in the sleeve 1-5 and upon energization of the solenoid is adapted to be projected beyond the upperend thereof and struck against the gong 12 the rim portion of which is in alignment with the direction ofmovement of the plunger.

The thermostatic switch is, in the present inestance, in the form of a bowed .bi-metallic element 18 which is mounted upon the plate 10 rearwardly of the sleeve 15 and which under normal temperature .has' its ends in spaced relation. Said emds carry contacts 119 one of which is joined to the source of current supply through the conductor 20 while the other is connected to conductor 21.

Also mounted upon the plate 10 on opposite sides of the sleeve 15 are a pair of terminals 22 having spring contacts 23 which project into the opening 16 in said sleeve so as to be engaged by the plunger 17 when the solenoid is de-energized. One of said terminals 22 is connected to the conductor 21 while the other is connected to the lower end of the winding of the solenoid. The casing 7 is preferably provided with a plurality of apertures 24 therein for the free admission of heat into the casing so that when the temperature therein increases and finally reaches a predetermined point the thermostatic element 18, affected by said increase of temperature, will contract and close the contacts 19. The circuit is thereby closed for the energization of the solenoid 13 which causes the plunger 17 thereof to rise through the bore of the solenoid and strike the gong 12 and sound an audible signal. As the plunger 1'7 rises the lower end thereof passes between the contacts 23 thereby breakingthe energizing circuit for the solenoid at this point. The plunger now returns toward its normal position by gravity and upon again engaging the spring contacts 23the energizing circuit for the solenoid is again closed and the same operation of sounding the signal is repeated. This operation continues until the surrounding temperature is reduced to the point where the contacts 19 are separated to permanently open the circuit for the solenoid. Then, upon deenergization of said solenoid, the plunger returns to its lower position by gravity.

In Figs. 4 to 6 the casing 25 is of substantially the same construction as the casing 7 and is supm5 ported by a bracket 26. An upper plate 27 is secured to the casing and projects therefrom, having fastened to its outer end a. supporting member or strip 28 the lower end of which is fixed to the bottom of the casing. Intermediate its ends the member 28 is offset as indicated at 29 to pro-. vide a means for attaching the lower plate 30 thereto. Mounted between the plates 27 and 30 is the solenoid 31 one end of the winding of which is connected to a conductor 32 which leads to the contact 33 of a normally open thermostatic switch thebigmetallic contact 34 of whichis carried bytheplat 30.

The solenoid 31 has a plunger 35 which no rmally extends below the plate 38 and engages a pair of spring contacts 36 one of which is cone nected to the winding of the solenoid and the other to the conductor 3'7 leading to the source of current supply. Uponclosure of the thermo static switch, due to heatenteringthe casing-2d through the apertures 38 therein, the circuit for energizing the solenoid 31 is closed through said switch, contacts 36 and plunger 35, whereupon the latter is projected upwardly and beyondthecasi+ ing 25 until it strikes the gong 39 supported by the member 28': As soonas' the plunger3'5 is disengaged from the contacts'36 the energizing clrcult fer the solenoid 31 is opened and the plunger drops by gravity, until it again engages said contacts, thereby ag'ain closing the circuitfor the solenoid. '.This operation is repeated as long as the thermostatic switch remains closed, thus intermittently operating the/audible alarm.

What is claimed is: 1 a

I 1'. In a fire detecting and alarming device, a U -shaped bracket having attached thereto shelves of insulating material, a solenoid mounted on the upper shelf, a metallic tube of non-magnetic material passing through the center of the solenoid, a plunger of magnetic and conducting material slidable in said tube, said plunger having atapered nose, a pair of spacedflat spring contact members mounted on the lower shelf between which ..s aid -.plunger is adapted to be forced by grayity,xa,. Leasing-1 to whichisaid bracket isattached, and a bell attached to said bracket, said solenoid being in series circuit with the spring \contact members, said plunger when in contact with the spring contact members closing a circuit through the solenoid;

qz ln-lafiredetecting and alarm device a U- shaped bracket-having attached thereto shelves 'ofirisulating material, a solenoid mounted on the upper. shelf, a tube of non-magnetic material passing through the center of the solenoid, a ,plungeriti'ofi magnetic and conducting material 4.16mi. Foam 

